Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

фotdr and sensing method based on optical frequency modulation and direct detection

A photodetector, optical frequency technology, applied in the direction of using optical devices to transmit sensing components, converting sensor outputs, measuring devices, etc., can solve problems such as system performance degradation, achieve high sensitivity, avoid coherent fading phenomenon, and suppress coherent fading. effect of the phenomenon

Active Publication Date: 2020-08-07
NAT UNIV OF DEFENSE TECH
View PDF6 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] Aiming at the problem of coherent fading in the ФOTDR system and the system performance degradation caused by it, the present invention proposes a phase sensitive optical time domain reflectometer and sensing method based on optical frequency modulation and direct detection
The invention performs sinusoidal optical frequency modulation on single-frequency tunable laser

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • фotdr and sensing method based on optical frequency modulation and direct detection

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0027] The specific implementation manners of the present invention will be described in further detail below in conjunction with the accompanying drawings.

[0028] see figure 1 , the present invention consists of a signal generator 1, a single-frequency tunable laser 2, a pulse generator 3, an optical amplifier 4, a narrowband filter 5, a circulator 6, a sensing fiber 7, a photodetector 8 and a signal acquisition and processing system 9 composition. The output port 11 of the signal generator 1 is connected to the modulation port 21 of the single-frequency tunable laser 2; the output port 22 of the single-frequency tunable laser 2 is connected to the input port 31 of the pulse generator 3 The output port 32 of the pulse generator 3 is connected to the input port 41 of the optical amplifier 4; the output port 42 of the optical amplifier 4 is connected to the input port of the narrowband filter 5; the narrowband filter 5 The output port 52 of the circulator 6 is connected to ...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The present invention relates to the distributed optical fiber sensing technology field, in particular to an optical frequency modulation and direct detection-based Phi OTDR and a sensing method thereof. The optical frequency modulation and direct detection-based Phi OTDR comprises a signal generator, a single frequency tunable laser, a pulse generator, an optical amplifier, a narrow band filter,a circulator, a sensing optical fiber, a photoelectric detector and a signal acquisition and processing system. According to the present invention, by carrying out the sine optical frequency modulation on a light source, the Rayleigh scattering light intensity at the positions of the sensing optical fiber generates the periodic modulation, thereby suppressing a coherent fading phenomenon in a PhiOTDR system. Meanwhile, the periodic variation of the Rayleigh scattering light intensity realizes the effect of a carrier wave, an external signal is loaded in the carrier wave, a Rayleigh scatteringsignal is detected by the photoelectric detector directly, and the frequency information of the Rayleigh scattering signal can be obtained by the Fourier transform, thereby sensing the external signal. According to the present invention, a system sensitivity decline problem caused by the coherent fading is avoided, thereby guaranteeing the good signal to noise ratio at all positions of the wholesegment of sensing optical fiber.

Description

technical field [0001] The invention relates to the technical field of distributed optical fiber sensing, in particular to a phase sensitive optical time domain reflectometer (ФOTDR) and a sensing method based on optical frequency modulation and direct detection. Background technique [0002] The phase-sensitive optical time domain reflectometer system has great application value in the fields of perimeter security, seismic wave detection, oil exploration and distributed acoustic sensing. Compared with other distributed optical fiber sensing systems, ФOTDR has comprehensive advantages in signal-to-noise ratio, system complexity, response frequency, detection sensitivity, etc., and has received high attention in the field of high-sensitivity dynamic distributed measurement. The intensity of the Rayleigh scattering signal is directly detected by photodetectors, and the frequency information of the external signal can be obtained directly through Fourier transform. This soluti...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Patents(China)
IPC IPC(8): G01D5/353
CPCG01D5/35361
Inventor 孟洲胡晓阳路阳王建飞张学亮余志杰陈伟孙世林陈默陈羽梁朝里
Owner NAT UNIV OF DEFENSE TECH
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com